Uncovering Lasonolide A Biosynthesis Using Genome-Resolved Metagenomics.

Invertebrates, particularly sponges, have been a dominant source of new marine natural products. For example, lasonolide A (LSA) is a potential anticancer molecule isolated from the marine sponge sp., with nanomolar growth inhibitory activity and a unique cytotoxicity profile against the National Cancer Institute 60-cell-line screen.

Discovery of unusual dimeric piperazyl cyclopeptides encoded by a DSM 44664 biosynthetic supercluster.

Rare actinomycetes represent an underexploited source of new bioactive compounds. Here, we report the use of a targeted metabologenomic approach to identify piperazyl compounds in the rare actinomycete Lentzea flaviverrucosa DSM 44664. These efforts to identify molecules that incorporate piperazate building blocks resulted in the discovery and structural elucidation of two dimeric biaryl-cyclohexapeptides, petrichorins A and B.

A Capture Strategy for the Identification of Thio-Templated Metabolites.

Nonribosomal peptide synthetase and polyketide synthase systems are home to complex enzymology and produce compounds of great therapeutic value. Despite this, they have continued to be difficult to characterize due to their substrates remaining enzyme-bound by a thioester bond. Here, we have developed a strategy to directly trap and characterize the thioester-bound enzyme intermediates and applied the strategy to the azinomycin biosynthetic pathway.

A comparative metabologenomic approach reveals mechanistic insights into antibiotic crypticity.

genomes harbor numerous, biosynthetic gene clusters (BGCs) encoding for drug-like compounds. While some of these BGCs readily yield expected products, many do not. Biosynthetic crypticity represents a significant hurdle to drug discovery, and the biological mechanisms that underpin it remain poorly understood.

Draft Genome Sequences of Two Polycyclic Tetramate Macrolactam Producers, sp. Strains JV180 and SP18CM02.

Here, we report the draft genome sequences of two related sp. strains, JV180 and SP18CM02. Despite their isolation from soils in Connecticut and Missouri (USA), respectively, they are strikingly similar in gene content.

Nocardiopsistins A-C: New angucyclines with anti-MRSA activity isolated from a marine sponge-derived sp. HB-J378.

Marine natural products have become an increasingly important source of new drug leads during recent years. In an attempt to identify novel anti-microbial natural products by bioprospecting deep-sea Actinobacteria, three new angucyclines, nocardiopsistins A-C, were isolated from sp. strain HB-J378.

Streptomycetes: Surrogate hosts for the genetic manipulation of biosynthetic gene clusters and production of natural products.

Due to the worldwide prevalence of multidrug-resistant pathogens and high incidence of diseases such as cancer, there is an urgent need for the discovery and development of new drugs. Nearly half of the FDA-approved drugs are derived from natural products that are produced by living organisms, mainly bacteria, fungi, and plants. Commercial development is often limited by the low yield of the desired compounds expressed by the native producers.

Priming of Azabicycle Biosynthesis in the Azinomycin Class of Antitumor Agents.

The biosynthesis of the azabicyclic ring system of the azinomycin family of antitumor agents represents the "crown jewel" of the pathway and is a complex process involving at least 14 enzymatic steps. This study reports on the first biosynthetic step, the inroads, in the construction of the novel aziridino [1,2-a]pyrrolidine, azabicyclic core, allowing us to support a new mechanism for azabicycle formation.

Probing the Role of N-Acetyl-glutamyl 5-Phosphate, an Acyl Phosphate, in the Construction of the Azabicycle Moiety of the Azinomycins.

The azinomycins are potent antitumor agents produced by the soil bacterium Streptomyces sahachiroi and contain a novel aziridino[1,2-a]pyrrolidine core; its synthesis involves at least 14 steps. This study reports the first reconstitution of N-acetylglutamine semialdehyde formation by two enzymes encoded in the azinomycin biosynthetic gene cluster. The reaction proceeds through the formation of an acylphosphate and establishes N-acetyl-glutamyl 5-phosphate and N-acetylglutamine semialdehyde as intermediates in the complex biosynthesis of the aziridino[1,2-a]pyrrolidine moiety.

Discovery of parallel pathways of kanamycin biosynthesis allows antibiotic manipulation.

Kanamycin is one of the most widely used antibiotics, yet its biosynthetic pathway remains unclear. Current proposals suggest that the kanamycin biosynthetic products are linearly related via single enzymatic transformations. To explore this system, we have reconstructed the entire biosynthetic pathway through the heterologous expression of combinations of putative biosynthetic genes from Streptomyces kanamyceticus in the non-aminoglycoside-producing Streptomyces venezuelae.

Biosynthetic approach for the production of new aminoglycoside derivative.

Aminoglycoside antibiotics can be classified into two major groups; streptamine containing and 2-deoxystreptamine containing antibiotics. Here, we report a biosynthetic approach for the fusion of spectinomycin and kanamycin biosynthetic gene clusters to yield the new aminoglycoside derivative, oxykanamycinC, in a non-aminoglycoside producing heterologous host.

Functional characterization of KanP, a methyltransferase from the kanamycin biosynthetic gene cluster of Streptomyces kanamyceticus.

KanP, a putative methyltransferase, is located in the kanamycin biosynthetic gene cluster of Streptomyces kanamyceticus ATCC12853. Amino acid sequence analysis of KanP revealed the presence of S-adenosyl-L-methionine binding motifs, which are present in other O-methyltransferases. The kanP gene was expressed in Escherichia coli BL21 (DE3) to generate the E.

Heterologous production of paromamine in Streptomyces lividans TK24 using kanamycin biosynthetic genes from Streptomyces kanamyceticus ATCC12853.

The 2-deoxystreptamine and paromamine are two key intermediates in kanamycin biosynthesis. In the present study, pSK-2 and pSK-7 recombinant plasmids were constructed with two combinations of genes: kanABK and kanABKF and kacA respectively from kanamycin producer Streptomyces kanamyceticus ATCC12853. These plasmids were heterologously expressed into Streptomyces lividans TK24 independently and generated two recombinant strains named S.

Characterization of RbmD (glycosyltransferase in ribostamycin gene cluster) through neomycin production reconstituted from the engineered Streptomyces fradiae BS1.

Amino acid homology analysis predicted that rbmD, a putative glycosyltransferase from Streptomyces ribosidificus ATCC 21294, has the highest homology with neoD in neomycin biosynthesis. S. fradiae BS1, in which the production of neomycin was abolished, was generated by disruption of the neoD gene in the neomycin producer S.